Hydraulic press



Dec. 8, 1970 E. E. GRANKowsgLF-TAL HYDRAULIC PREss m a. m um n@ wwqw www QQW om mw wm www WQ w mm, A www. m.

United States Patent 3,545,241 HYDRAULIC PRESS Eugene E. Grankowski and Lambros Pappas, Chicago,

lll., assignors to Verson Allsteel Press Company, Chicago, Ill., a corporation of Delaware Filed Apr. 22, 1968, Ser. No. 723,118 Int. Cl. B21d 22/12 U.S. Cl. 72-63 i 7 Claims ABSTRACT `OF THE DISCLOSURE The present invention relates to a novel work forming press, and more specifically to a novel hydraulic press.

Structures of a general type contemplated herein have usually included cylinder or body means defining a cavity, a hydraulically expandable bag or fluid cell and diaphragm mounted within the cavi-ty, and la tray or support member movable into and out of the cavity. During operation of the structure, a workpiece to be processed is positioned on a mold or form on the tray which is then inserted within the cavity. Upon introduction of hydraulic fluid under pressure, the diaphagm is expanded and causes the workpiece to conform closely to the mold. Reaction forces which occur are absorbed and sustained by the cylinder or body means.

While presses of the above described type have been successfully operated, these structures have been such that reaction forces are `transmitted to the surrounding cylinder or body means unevenly. In certain instances, the uneven loading of the cylinder or body means has resulted in sufciently high concentrations of stresses in limited areas to cause failure. 4

It is an important object of the present .invention to provide an novel hydraulic press of the above described type which is constructed so that reaction; forces within the press are more uniformly distributed for minimizing any possibility of failure A more specific object of the present invention is to provide a novel hydraulic press of the above described type having cylinder or body means, an expandable diaphragm or bag and a work supporting tray and further l incorporating cylinder means operated by fluid pressure simultaneously with the diaphragmorfluid cell for distributingreaction forces more uniformly.

Other objects and advantages ofthe present invention will become 4apparent from the followingdescription and the accompanying drawings wherein:

FIG. 1 is asimplified perspective view showing a` press incorporating features of thepresent invention;

FIG. 2 is an end view of the apparatus shown in FIG. 1; p FIG. 3 is an enlarged fragmentary sectional view taken lalong line 3--3 in FIG. 4; Y

FIG. 4 is a fragmentary sectional view taken along line 4 4 in FIG. 3; and

FIG. 5 is a fragmentary sectional view taken along line 5-5 in FIG. 4.

Patented Dec. 8, 1970 ICC Referring now more specifically to the` drawings wherein like parts are designatedby the same numerals throughout the various figures, a press 10 incorporating features of the present invention is shown in FIGS.,1 and 2. The press comprises cylinder or body means 12 to be described `.in detail below mounted on a suitable frame 14. `Thebody means defines a cavity into which a work `supporting tray may be inserted from table extensions 16. and 18 `at opposite ends of the body. l

A suitable .source of hydraulic iiuid underpressure is provided` for actuating the press. In the embodimentldisclosed herein this comprises a pump and motor unit 20 shown schematically in FIGS. 2'and 4 having an Ainlet connected with .a reservoir `22 and an outlet connected with a control Valve 24. This valve is connected with conduit means 26 having various branches extending to different portions of the press as will be described below. The valve also has a vent port connected by a return line 28 to the reservoir.

As shown in FIGS. 3-5, the cylinder or body means 12 comprises an inner cylinder 30 and a laminated outer cylinder 32 having a plurality of layers 33 formed from sectionswelded together as at 35. These cylinders are made from a suitable metal such as steel. Flanges 37 encircle opposite ends of the cylinder 32 and the ends of the laminations are covered by annular end plates 39 shown lin FIG. 4. v

The body means comprising the inner and outer cylinders defines a cavity 34. An upper portion of this cavity is filled by a relatively heavy vand rigid roof casting 36 and a complementary thick and relatively rigid roof plate 38. A lower portion of the cavity is filled by .a relatively heavy and rigid floor casting 40. Thus, the inner surfaces of the roof and the floor define relatively rigid upper and lower sides of the work cavity within the press.

A tray 42 is slidable into the work cavity 34 on bearing strips or rails 44 and 46 extending along the floor casting 40. As previously indicated, this tray may be inserted .into the cavity from tables 16 or 18 extending oppositely from the body means. If desired, the apparatus may be provided with two trays so that one may be positioned within the cavity while the other is being loaded or unloaded at a retracted position on one of the side tables.

The tray 42 has a relatively thick and `rigid bottom section 48. Opposite sides and 52 and opposite ends 54, only one of which is shown, extend upwardly from the bottom section 48 for defining a work retaining recess 56.

A hydraulically expandable bag or uidpressure cell 58 is scured beneath the roof plate 38 and connected with an inlet port 60. A relatively thick and wear .resistant rubber pad or diaphragm l62 is disposed immediately beneath the cell. As will be understood, when the pressure cell is expanded by the introduction of hydraulic fluid under pressure, the diaphragm or pad 62 will be extended downwardly into the cavity 34 for forming engagement with a l workpiece supported by the tray y42. As indicated in FIG.

4, thickened opposite end portions 64 of the roof plate 38 cooperate with means described below for effectively closing the opposite ends of the cavityl 34.

In order to secure and support the oppositeside margins of the diaphragm,` side railmembers 66 and and `68 are disposed within the inner cylinder. Outer surfaces of these side rail members are segments of a cylinder and mate with the interior surface of the member 30. Inner surfaces ofthe side rails have first inclined portions 70 andr72mating with outwardly flaring or inclined surfaces of the tray side Walls 50 and 52. The inner surfaces of the side rails have upper sections 74 and 76 which extend substantially vertically from upper margins of the tray to the diaphragm or pad 62 as shown n FIGS. 3 and 5.

In order to seal the space between the upper edge of the tray and the diaphragm or pad, a sealing block 78 is mounted on and carried by the tray. This block has opposite side sections 80 and 82 mating with the surfaces 74 and 76 and having downwardly and inwardly beveled inner side surfaces 84 and 86. The sealing block has opposite end portions 88, only one of which is shown in FIG. 4'and which have depending keys 90 interengaging with the tray. The end portions also have downwardly and inwardly inclined inner surfaces 92 and upper surfaces cooperating substantiallyv with the thickened portion l64 of the roof plate for substantially sealing the opposite ends of the cavity. In addition, spring seals 94, only one of which is shown, are disposed between the opposite thickened end 4portion 64 of the roof plate and the opposite end portions 88 of the block respectively for retaining the opposite ends of the diaphragm or pressure pad 62 insuring complete sealing of opposite ends of the cavity during the operation of the press.

As previously indicated, when hydraulic fluid under pressure is introduced into the pressure cell, the diaphragm or pad `62 is expanded downwardly for forming the work. At the same time, the diaphragm is pressed tightly against the inner beveled surfaces of the sealing block 78 and similarly inwardly beveled or inclined surfaces of the opposite sides and end walls of the tray. Central portions of the roof and floor members 36, 38 and 40 are relatively thick and rigid as compared with opposrsite marginal portions thereof and also as compared With the opposite side rails 66 and 68. Thus, there is a tendency for different portions of the structure to flex different amounts under the reaction forces during operation of the press so that there is a severe non-uniformity in the radial loading of the cylinder or body means.

In accordance with a feature of the present invention, the apparatus is provided with means for more uniformly distributing the reaction loads to the cylinder or body structure. This means comprises a plurality of hydraulic cylinders 96 and cooperating pistons 98 spaced along the side rail 66 as shown in FIGS. 3 and 4. In addition, identical 'but oppositely disposed cylinders 100 and cooperating pistons 102 are spaced along the side rail 68. These cylinders are disposed so that their respective pistons abut and mate with the inclined outer surfaces of the tray side walls 50 and 52.

Inlet ports of the cylinders 96 are connected with a passageway 104 extending longitudinally of the side rail `66 and inlet ports of the cylinders 100 are connected with a similarlongitudinally extending passageway 106 in the side rail 68. These passageways are respectively connected with the hydraulic supply line 26 by suitable branch conduits 108 as indicated schematically in FIG. 4. Furthermore, it is seen that the hydraulic supply line 26 is connected by branch conduit 110 with a passageway 112 in the roof plate 38, which passageway communicates with the inlet port 60 of the hydraulic cell or bag 58.

With the structure' described above, it is seen that when the control valve 24 is actuated for admitting hydraulic iiuid under pressure to the line 26, the uid is directed simultaneously to the cell or bag 58 and to the cylinders 96 and 100. Thus, as the fluid pressure cell and diaphragm expand and press against the sides of the sealing block 78 and against the tray, the pressure within the side cylinders 96 and 100 builds up and is essentially equal to the pressure within the fluid cell. Thus, the pressure within the cylinders balances the reaction forces against the side walls of the tray and imposes the same reaction forces on lower portions of the side rails 66 and 68. In other words, pressure is applied to the upper portions of the side rails 66 and 68 from the fluid cell and the diaphragm and similar pressures are applied to the lower portions of the side rails through the side cylinders 96 and 100. As a result, the reaction forces within the press are more uniformly distributed to the cylinder or body structure. Of course, when the control valve 24 is actuated for venting the pressure cell 58, the pressure within the cylinders 96 and 100 is simultaneously relieved.

During operation of the press, there is a tendency for the cylinder or body structure to be deformed into a slightly elliptical configuration with the major axis coinciding with the vertical axis of the press as seen in FIG. 3. Such non-uniformity of pressure distribution tends to cause areas of high stress concentration as previously discussed, which areas include areas adjacent corners 114 and 116 of the floor casting as shown in FIG. 3. However, with the previously described structure and operation of the press in accordance with the present invention, the relatively uniform application of radial forces through the side rails 66 and 68 to the cylinder structure resists and minimizes or eliminates the tendency of the cylinder structure to assume an elliptical configuration and prevents the buildup or concentration of stresses in limited critical areas.

While a preferred embodiment of the invention has been shown and described herein, it is obvious that many structural details may be changed without departing from the spirit and scope of the appended claims.

The invention is claimed as follows:

1. In a hydraulic press, the combination comprising cylindrical body means defining a cavity, a work support member within said cavity for supporting work to be processed, expandable fluid pressure cell means mounted in said cavity oppositely from said work support member for processing the work, and means within said cavity for imparting radial loads to generally opposite portions of said body means located adjacent opposite sides of said work support member for minimizing deformation of and stress concentrations in said body means during processing of the work.

2. A combination, as defined in claim 1, which includes opposed relatively thick and rigid roof and iioor members in said cavity and respectively between said cell means and the body means and said work support member and the body means.

3. A combination, as defined in claim 1, which includes side rail members disposed between said body means and Opposite sides of said work support member, and said means for imparting radial loads to the body means comprising means for urging said side rail members against the body means.

4. A combination, as defined in claim 3, wherein said means for imparting radial loads to the body means comprises liuid pressure cylinder and piston means disposed within each of said side rail members.

5. A combination, as defined in claim 4, which includes means for supplying hydraulic fluid under pressure simultaneously to said fluid cell means and to said piston and cylinder means during processing of the work.

6. A combination, as defined in claim 4, wherein said means for imparting radial loads to the body means comprises a plurality oE said cylinder and piston means spaced along each of said side rail members and respectively having pistons abutting said Work support member.

7. A combination, as defined in claim 1, which includes a roof structure disposed between said fluid cell means and `said body means, a fioor structure disposed between said work support member and said body means, said tray member including a bottom section and wall sections extending upwardly therefrom for defining a recess and terminating in spaced relationship with respect to said roof structure and said fluid cell means, a sealing block on said work support member extending around said recess and substantially between said work support member and said fluid cell means, opposite side rail members extending along opposite sides of said work support member` and substantially between said floor structure and said cell means, said rail members having inner surfaces substantially mating with outer side surfaces of said work support member and said sealing block, and said means for imparting radial loads to said body means including uid pressure cylinder and piston means disposed in said side rail members and engageable with said opposite sides of the work support member beneath said sealing block.

References Cited UNITED STATES PATENTS 2,771,850 11/ 1956 Wheelon 72-63 2,848,968 8/'195 8 Novals 18--High Pressure Dept.

6 Gerrard et al.

18-High Pressure Dept. Gerrard et al.

18High Pressure Dept. Von Platen 18-High Pressure Dept. Pfeiffer et al 72-63 U.S. Cl. XJR.

UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Parent No. 3,545,241 Dated l2es;emb er i. l21 0 Inventor(s) Eugene E. Grankowsk; and Lambros Pappas It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 6l, after "66 and" omit -and;

Column 3, line 23, after "62" insert -and;

Column 4, line 68, change "tray" to --work support-- Sfgned and sealed this 29th day of June 1971.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JI Attestng Officer Commissioner' of Patent: 

